Species

Etymology

Coriaria: From the Latin corium 'hide', possibly from the use of some species for tanning leatherarborea: From the Latin arbor 'tree', meaning tree-like

Common Name(s)

tutu, tree tutu

Current Conservation Status

2012 - Not Threatened

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - Not Threatened
2004 - Not Threatened

Authority

Coriaria arborea R.Linds. var. arborea

Family

Coriariaceae

Brief Description

Common robust much-branched large shrub inhabiting disturbed areas. Twigs square in cross-section, bearing pairs of 50-80mm long glossy green elliptical leaves that do not have a leaf stalk. Flowers in drooping spikes up to 30cm long. Fruit black.

Flora Category

Vascular - Native

NVS Species Code

CORAVA

The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.

Structural Class

Dicotyledonous Trees & Shrubs

Flower Colours

Green

Threats

Not Threatened

Chromosome No.

2n = 40

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Fleshy berries are dispersed by frugivory (Thorsen et al., 2009).

Poisonous plant

Tutu is the classic poisonous plant of NZ. It is a widely distributed native species found throughout New Zealand, particularly along stream banks and in regenerating native bush. Some of the first animals introduced to NZ by Captain Cook in the 18th Century were poisoned by it. The plant caused losses in cattle and sheep. All parts of all Coriaria species are poisonous except the succulent black, soft fleshy petals surrounding the seeds (the seeds themselves are also poisonous). Poisoning is usually through eating the seeds, berries or poisonous honey.

Tutin acts on the central nervous system leading to symptoms of nausea, vomiting, burred vision, weakness and seizures or convulsions and can lead to a comatose state. Breathing is usually affected, so too is memory.

Toxic honey is contaminated as a result of bees visiting tutu (Coriaria arborea) with honey dew being excreted onto the leaves of the plant by the tiny toxic sap sucking passion vine hopper (Scolypopa australis) and then bees gathering the honeydew.

Tutin, and its derivative, hyenanchin are extremely toxic to humans, but only a few areas in NZ regularly produce toxic honey. These include the Coromandel Peninsula and Eastern Bay of Plenty and the Marlborough Sounds.

A number of people have been killed, incapacitated and hospitalised over the years from eating toxic honey. The last recorded case from commercial honey was in 1974 involving 13 patients. There have been 9 cases since 1974 with the last known poisonings occurring in 1991 in the Eastern Bay of Plenty area and 2008 in the Coromandel.